The present invention relates to a durable, single-piece hanger for use in applying an electrostatic powder coating to tubular objects such as automotive exhaust components. Electrostatic powder coating comprises the application of electrostatically-charged coating particles to target work pieces having an opposite electrostatic charge. The coating powder which is applied in the process is extremely fine and carries easily within a coating booth to facilitate uniform coating of the target work pieces.
Typical powder coating apparatus for use in coating tubular exhaust components comprises a moving chain conveyor for carrying target components past stationary powder spray heads within a coating booth. It has been common practice to use conventional vice grips for attaching the tubing target to hooks depending from a chain conveyor. The jaws of the vice grips are clamped over a wall of the tubular component to be sprayed and a handle of the grip is then attached to a conveyor hook for carrying the component through the spray booth.
Because the vice grip is thus attached to the target component it necessarily carries the same electrostatic charge as the component. The result is that when the vice grip, carrying the tubular component, passes in front of the spray head the grip is uniformly coated with the powder, as is the target component.
In mass production operations, wherein the vice grip tube hanger is reused hundreds of times during a single day's production, the conventional vice grip suffers a powder build-up inside of its working components which eventually causes it to fail. Repair or replacement of the vice grips--especially on a mass assembly basis--is costly and time consuming.
The hanger of the present invention was designed to overcome the problems caused by the vice grips as used in an electrostatic coating process. The hanger is one-piece construction and is shaped in a novel manner in order to preclude failures even after thousands of uses in the coating process.